The Environmental Management Agency (EMA) yesterday accused City of Harare of not taking action over the pollution at Lake Chivero, the city's main water supply reservoir.
In a statement yesterday, EMA Harare provincial environmental manager Mr Robson Mavondo said the agency identified Harare City Council as the main polluter by discharging raw sewage into the lake.
"As EMA, we identified Harare City Council as the main source of pollution for raw sewer discharge into the environment," he said.
"City of Harare and Ruwa Local Board were recently taken to court for being the major polluters in the city."
Mr Mavondo said many industrial and domestic activities taking place in the opposition MDC-Alliance-run local councils were affecting the quality of water in rivers.
"Many industrial, agricultural and domestic activities taking place in the city and from surrounding towns are affecting the quality of water in Mukuvisi, Manyame and Ruwa rivers," he said.
"Some of the activities include sewer and solid waste disposal from sewer treatment facilities and industrial discharges from industrial zones."
Mr Mavondo said EMA will continue monitoring the quality of water along Marimba and Mukuvisi rivers.
"EMA will continue regulating the quality of ambient water along Marimba and Mukuvisi rivers through the collection of water samples from these rivers once every month," he said.
Speaking during the National Clean up Day in March, President Mnangagwa described as shameless litterbugs and elements that have polluted Lake Chivero.
He said Government would soon act to deal with those found on the wrong side of the law.
The President deplored the near extinction of fish in the lake due to pollution.
"How this water that used to be blue and clean, now is green and dirty?" said President Mnangagwa. "That was exposed to us in the briefing and it is the duty of the leadership to address that.
"I challenge residents, business and vendors to dispose of waste at rightful places. We were told that we are losing fish in numbers in the lake because of dirt. Let us be ashamed of our behaviour."